Sump pump discharge pipe: the standing water trap!

I've read of a bunch of other posts on this issue. I guess everyone with this problem has a unique situation and here's mine. I used a paint tool to make super awesome graphics for all you plumbers.

The first picture is the way things are now. I have a 1.5 inch PVC pipe buried in a trench and it seems to be between 1/8 and 1/4 inches per foot sloped away from the house. Previously the pipe had stopped and done a 90 degree upturn at the sidewalk. From there, I had flex pipe and every time there was a rain I would have to roll the flex pipe out over the sidewalk to the road. The flex pipe is destroyed, the actual PVC piping is good.

The second picture shows what I'd like to do. Notice that because the PVC pipe is sloped downward away from the house it is also below the curb. So there will be water that is standing. For example, the proposed pipe in red will continue the downward slope, and water that does not make it out will sit. So I am trying to resolve this issue. I thought maybe I would put tiny pinholes in the PVC at its lowest point and while normal pressure would push the water up and out, any sitting water would slowly seep through the pinholes.

I live in Southern N.Y. and my concern is that standing water in the pipe could freeze and block discharge. Although this hasn't happened yet that I know of. For various reasons I cannot build up the grade of soil to slope it away from the house.

Sump pump discharge pipe: the standing water trap!

Sump pump discharge pipe: the standing water trap!

Your solution is fine, I suggest a single 1/4 inch diameter hole on the underside of the pipe. Surround the pipe with filter fabric in the vicinity of the hole, that will stop clogging. During normal operations, most of the water will pump up to the curb, when the pump stops water will drain, as you observed.

The only concern is whether your community is aware that you have a sump pump connection to the street, in some towns this requires a permit, and in some cases is not allowed.

Sump pump discharge pipe: the standing water trap!

Your neighbors are going to hate you in the winter when that pump kicks on and turns the street in front of your house into a skating rink. Hopefully you are discharging right into a storm drain but by your pics this does not seem to be the case.

Sump pump discharge pipe: the standing water trap!

When you use the system all winter long and there is a long cold snap, water can become caked to the inside of the pipe which will eventually be frozen solid.

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